File size difference with Vuescan vs. Silverfast

I'm wondering why my Silverfast scan file results are approximately twice the size of my Vuescan files. I scan both
with the same dpi and the same 24 bit color, and when I double check the results in an image editor, the file info
shows the same number of pixels in the width and height and the same color depth. They're both TIFF files, but
even when I save the Silverfast file as a BMP and as a different named file, the file size is still double.

When I multiply out the horizontal and vertical pixel numbers, the vuescan file is right on the money with regard to
file size. Also, the bundled Epson scanning software that came with the V700 gives the same file sizes as the
Vuescan software, so I'm thinking something is out of whack with my Silverfast settings.

Any thoughts?

Thanks in advance.

Responses

Are all the tif files the same size? If they are then nothing wrong, just use the tif file. Why save the file as a bmp, then
the difference is the bmp format, which is considerably larger in size due to the data structure, see article. I've never had problems with Silverfast on my V750,
and prefer it to the Epson software.

Vuescan's tiff compression was the *only* application I've ever seen where the result *was* smaller, not bigger, as you mentioned. Photoshop tiff compression did nothing *but* increase file sizes, in my experience. All said, I found tiff compression a waste of time, and possibly risky.

Vuescan's tiff compression in my experience, with grainy scans, was maybe 20% improvement. It could be with a smooth file you'd do better.

Ok, another guess, are these all b/w images, only the silverfast one is in rgb format? That would make a 3 fold difference though...

Scott K, sorry, the bmp was an unintentional red herring. Both files were originally tiff's.

Scott T, and Mendel. Vuescan's fine. It's the silverfast that's giving me double the file size. On the same 2,600 pixel by 2,000 pixel photo, the vuescan file size is 8 megapixels, while the silverfast is 15 megapixels. I know everything's being scanned at the same resolution, because when I zoom into details, the number of pixels showing on a tiny detail are exactly the same.

I've sent a query into silverfast. Hopefully they can shed some light. Thanks anyways.

Sorry, the bmp was just an attempt to reduce file sizes. All were originally tiff's.

Vuescan's fine. It's the silverfast that is the hog. On an identical scan with an output of 2,600 by 2,000 pixels, the
vuescan gives a file of 8 megapixels and the silverfast gives 15 megapixels. And I know the resolution is identical,
because when I do an extreme zoom, the number of pixels on a tiny detail are exactly the same.

I'm sending a query into silverfast to see if they can shed any light. Thanks anyways.

Dear Evan,
SilverFast saves TIFF-files in uncompressed standard TIFF-Format (24 or 48bit), so files are 100% compatible with most
imaging applications. If you want high quality lossless compression, use SilverFast Ai Studio, which supports JPEG 2000, which is also
supported by Photoshop as well as by SilverFast HDR Studio.
JPEG 2000 is the best compression supporting up to 16/48bit and can save lossy and lossless at high compression speed!